Overall, a total of approximately 1600 HIV+ pregnant women will participate in Phase 1 of the study over 12 months. From this group, it is anticipated that approximately 400-500 HIV+ pregnant women eligible for ART will be identified as eligible for Phase 2 participation. We estimate that of the approximately 600 women on ART followed in Phase 2, approximately 480 will be eligible for and enrolled into Phase 3 and randomized to one of two postpartum ART delivery strategies.